# Percentages Flashcards

## Na

Ratio to find all percentages

What is the Top Left Number

What is the Bottom Left Number

Top Right Number

Bottom Right Number

Top Left: Percentage

Bottom Left: 100

Top Right: Portion of the Whole

Bottom Right: The Whole Number

Formula for Percentage Change:

New number, Minus, Old number ,Divided by Old Number, Multipled by 100

Formula to convert Decmil to Percent

Move decmil over to the Right 2 places

( Make it Larger )

Or

Multiple by 100

Formula to convert Fraction to Percentage

Divide Top Number by Bottom Number

Multiply by 100

How do you convert Repeating decmils to fractions.

Examples

Put the repeating part over 9 followed by as many 9s as the repeating part

- THE NUMBERS BELOW ARE ALL REPEATING

.4 = 4/9

.35 = 36/99

.420 = 420/999

To get a Fraction from a Decmil with only a part of it repeating. Describe the Method

How do you confirm if you have the correct fraction?

Subtract the repating part from the non reating part but Move the repeating part to make it start a new decmil itself.

Take Subtracted Total and Repeating total and Change them to Decmils.(Remember Repeating Decmils go over 9(s) the same amount as the number of digits as the number.)

Add the decmils together ( Always Reduce )

To Confirm: Divide Top Number of Fraction by Bottom Number

Formula for finding New or Original Price with a Percentage involved.

Exp. Sneakers cost 133.75$ with a 7% Sales Tax.

What is the Original Price of the Sneakers

New = Original × (1 + or - Rate[Percentage as a Decmil] )

- 75 (New) = Original [X] × (1 + 0.07 [Rate])
- 75 = [X] × 1.07 Algebra Do the Opposite to get X alone. Divide both sides by 1.07
- 75 ÷ 1.07 = 125

Formula to Add ANY% to a number..

EXP.

Shoes cost 299$ what is the total with a 6% Sales tax?

Set up a proportion with

299 on bottom right

Formula to find Original Value when taxes are already included.

Exp.

Karen pays a total of 69.55 for a shirt with a 7% Sales Tax included. What is the Original price of the shirt.

New value 69.55 ÷ 1 + ( Percentage in Decmil form)

69.55 ÷ 1.07 = 65

Formula to find the Oringal Value when the Percentage Decrease has already been added.

Exp.

Karen pays 69.55$ for a shirt with a 7% discount already applied.

What is the Original Price of the shirt?

New Price 69.55 ÷ 1 - ( Percentage as a Decmil .07)

69.55 ÷ .93 = 74.78